A longitudinal study on urinary cadmium and renal tubular protein excretion of nickel-cadmium battery workers after cessation of cadmium exposure

Current Levels of Environmental Exposure to Cadmium in Industrialized Countries as a Risk Factor for Kidney Damage in the General Population: A Comprehensive Review of Available Data

The growing number of reports indicating unfavorable outcomes for human health upon environmental exposure to cadmium (Cd) have focused attention on the threat to the general population posed by this heavy metal. The kidney is a target organ during chronic Cd intoxication. The aim of this article was to critically review the available literature on the impact of the current levels of environmental exposure to this xenobiotic in industrialized countries on the kidney, and to evaluate the associated risk of organ damage, including chronic kidney disease (CKD). Based on a comprehensive review of the available data, we recognized that the observed adverse effect levels (NOAELs) of Cd concentration in the blood and urine for clinically relevant kidney damage (glomerular dysfunction) are 0.18 μg/L and 0.27 μg/g creatinine, respectively, whereas the lowest observed adverse effect levels (LOAELs) are >0.18 μg/L and >0.27 μg/g creatinine, respectively, which are within the lower range of concentrations noted in inhabitants of industrialized countries. In conclusion, the current levels of environmental exposure to Cd may increase the risk of clinically relevant kidney damage, resulting in, or at least contributing to, the development of CKD.

Cadmium exposure and early renal effects in the children and adults living in a tungsten-molybdenum mining areas of South China

Adverse health effects related to accumulative cadmium (Cd) exposure have aroused widespread attention from the public in China. Knowledge on the relationships between Cd exposure and early renal effects is particularly limited for children, who are more susceptible to absorbing metals than adults. A typical Cd-polluted area of South China was selected to determine the Cd exposure and related early renal effects of the general population, including children. In total, 211 children and 806 adults were enrolled in the study. The urinary levels of Cd (U-Cd), β₂-microglobulin (U-BMG), retinol binding protein (U-RBP), and N-acetyl-β-D-glucosaminidase (U-NAG) were measured. The relationship between U-Cd and ranked indicators of early renal effects was examined by multiple regression analysis. The average U-Cd ranged from 7.01 μg/g creatinine (boys) to 13.55 μg/g creatinine (women) in the Cd-polluted areas. These values are much higher than those of the control group and those that have been reported by other countries. In agreement with previous studies, environmental Cd pollution resulted in elevated Cd accumulation in the bodies of children, and it increased the concentration of NAG in their urine. Similarly, environmental Cd pollution increased NAG and BMG in the urine of adults. Multivariate models showed that the urinary excretion of BMG, RBP, and NAG was positively associated with Cd levels in the urine of both children and adults. The reference thresholds of U-Cd in relation to elevated U-BMG, U-RBP, and U-NAG were higher in children than adults after standardization for other covariates. These results reinforce the need to control and regulate the sources of environmental Cd contamination and to promote more effective risk management measures, especially for vulnerable groups.